#define _CRT_SECURE_NO_WARNINGS 1

https://leetcode.cn/problems/find-largest-value-in-each-tree-row/

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    vector<int> largestValues(TreeNode* root) {

        vector<int> result;
        queue<TreeNode*> que;

        if (root != NULL)   que.push(root);

        while (!que.empty())
        {
            int size = que.size();
            int max = que.front()->val;

            while (size--)
            {
                TreeNode* temp = que.front();
                que.pop();

                if (temp->val > max)    max = temp->val;

                if (temp->left)  que.push(temp->left);
                if (temp->right) que.push(temp->right);
            }
            result.push_back(max);
        }
        return result;
    }
};